Composition for inhibiting foam



Patented Nov. 9, 1948 COMPOSITION FOR INHIBITIN G FOAM Henry E. Tremain and Leslie R. Bacon, Wyandotte, Mich., assignors to Wyandotte Chemicals Corporation, Wyandotte, -Mich., a corporation of Michigan No Drawing. Application July 26, 1945, Serial No. 607,275

3-Claims.

1 The' present invention relates to a composition and a process for suppressing or inhibiting the formation of foam in aqueous systems or media, whether true solutions or colloidal suspensions,

such as encountered in industrial processes, for

example, industrial, alkaline cleaning operations, distillation, paper making, textile treating and finishing, glue manufacture, sugar boiling and soap'manufacture; The prevention of foaming difiiculties in commercial bottle washing machines employing alkaline washing solutions constitutes a field of application to which our invention is particularly adapted.

In our co-pending application Serial No. 520,- 960, filed February 3, 1944, now U. S. Patent No. 2,407,589, we have disclosed a foam inhibitor and a process for suppressing the formation of foam in which the major active ingredient is di-tertiary amyl phenoxyethanol or p-tertiary amyl phenoxyethanol. These two compounds have displayed unusual foam inhibiting properties, not only with respect to their ability to knock down foam which has already been formed in an industrial chemical process aqueous system, but also with respect to their ability to maintain foam suppression for relatively long periods of time. Ascompared to foam inhibiting compositions heretofore known and used, the above mentioned compounds of our aforesaid co-pending application, when tested both in the field and in the laboratory under similar rigorous conditions, have displayed vastly superior foam inhibiting properties;

In our co-pending U. S. patent application Serial No. 607,276, filed July 26, 1945, we have disclosed that other related amyl phenoxy alkanols, such as di-tertiary amyl phenoxyp fopanol and (ii-tertiary amyl phenoxy isopropanol are also excellent foam inhibiting compounds. These amyl phenoxy alkanols are in normally liquid form and somewhat viscous. They need be present in an aqueous body in but an unusually small amount in order to produce foam suppression, viz., as-low as 0.001% by weight. For 'even the most severe foaming conditions, one part of the foam inhibiting amyl phenoxy alkanol to 1000 parts of aqueous body has proven to be satisfactory for knocking down foam, and holding it down. Due to the physical properties of these amyl phenoxy alkanols and the relatively small quantities in which they need be used, whereby the likelihood of their .profligate use by unskilled or non-technically trained workers is quite possible, the problem has arisen of how to put 2 them up in a suitable form for packaging, handling and use.

Therefore, the general object and nature of the present invention has been to discover a relatively chemically inert but physically effective and inexpensive vehicle, or carrier for these amyl phenoxy alkanol compositions whereby they may be compounded in a convenient and suitable form for handling, packaging, and use in the solid state, such as in the form of a powdered or granulated mixture. We have found that sodium carbonate, such as light soda ash (as commercial form of sodium carbonate) constitutes a solid diluent or carrier for such amyl phenoxy alkanols which is particularly chemically and physically compatible with such organic compound.

A further unusual property of sodium car- Q bonate as a solid carrier is that it can adsorb as sodium bicarbonate and modified soda (a molecular combination of sodium bicarbonate and sodium carbonate). The following comparison serves as an excellent illustration of this unusual property of the compositions of our invention, showing the optimum amount of di-tertiary amyl phenoxyethanol that these alkali carbonates will take up in order to produce the commercially most satisfactory mixture:

Sodium bicarbonate will take up 5% di-tertiary amyl phenoxyethanol Modified soda will take up 10% di-tertiary amyl phenoxyethanol Soda ash will take up 25% di-tertiary amyl phenoxyetha'nol The values given above for the optimum amount of di-tertiary amyl phenoxyethanol that these alkali carbonates will take up is not the maximum amount (as hereinafter more fully described), but rather the amount that can be added so that the resultant mixture remains siftable" or nonpasty and still retains the physical appearance of the alkali carbonate itself. In other words, there is no visible evidence of the organic liquid being present, such as the leaving of an oily film on the fingers after handling. This unusual ability of sodium carbonate to absorb or take up the amyl phenoxy alkanols herein specified results in a most convenient physical form of product for actual use and handling, such as in a bottle washing plant, when the operator, if need be, may simply grasp a handful of 3 the material from its container and drop or sprinkle it into the washing machine.

We have devised a method of testing foam inhibiting properties reproducing as closely as pos- 4 We, therefore, particularly point out and dis-, tinctly claim as our invention:

l. A composition for suppressing the formation of foam in aqueous systems consisting of disible, the severest conditions of commercial foam 5 tertiary amyl phenoxyethanol and 50 to 90% by inhibiting problems. This test procedure is perweight anhydrous sodium carbonate.

formed in an apparatus which we have chosen 2. A composition for suppressing the formation to call a dynamic foaming machine" and is deof foam in aqueous systems consisting of approxiscribed in detail in our aforesaid Patent No. mately 25% by weight (ii-tertiary amyl phenoxy- 2,407,589. ethanol and approximately 75% by weight an- Several exemplary foam inhibiting compositions made according to the principle of our invention have been subjected to this test procedure, and the results thereof are set forth in the following table:

hydrous sodium carbonate.

3. A composition for suppressing the formation of foam in aqueous systems, consisting essentially of a compound selected from the group consisting of di-tertiary amyl phenoxyethanol, p-tertiary All percentages given herein are by weight unless otherwise specified.

In the case of the foam inhibitor compositions of our invention to 90% by weight of soda ash can be incorporated without detracting seriously from the desired physical properties of the resultant composition. Thus, with 50% di-tertiary amyl phenoxyethanol and 50% light soda ash, the composition does not cake, set up, pack, or drain liquid on standing. Where the soda ash is increased to 90% a satisfactory physical product results. without unduly sacrificing the foam inhibiting characteristics of the composition. The composition of Example 3 represents a most suitable preferred solid form of product in which soda ash is employed as the solid vehicle.

HENRY E. TREMAIN. LESLIE R. B ACON.

REFERENCES CITED The following references are of record in the file of this patent:

Minute amounts of dye may be added if it is de- 65 UNITED STATES PATENTS sired to impart a distinctive color to the composi- Number N t tion. Similarly, and for convenience in formula- 1, 31 Daimler Feb, 2, 1932 tion procedure, other known anti-foaming, but 1,999,630 Friesenhahn Apr. 30 9 5 substantially less effective, organic compounds 2,153,953 Coleman et 1 May 9 9 might be added in small amounts. Such other 2,158,959 Coleman et a1 May 1939 organic compounds are noted in our said co-pending application Serial No. 520,960, and include FOREIGN PATENTS tetradecanol, tri-octyl phosphate and several Number Country Date other alcohols and esters. 20,884 Great Britain 1901 Other modes of applying the principle of our invention may be employed, changes being made as regards to the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

OTHER REFERENCES 

